Figure 2.

Desorption of prebound ¹²⁵I-hFSH by hCG addition in cells coexpressing hLHR and hFSHR but not hFSHR only. HEK293 cells were transiently cotransfected with cDNAs encoding hLHR and hFSHR at submaximal levels (A) or with the same concentrations of empty vector plus hFSHR (B). On the day of the experiment, cells were preincubated with a saturating concentration of ¹²⁵I-hFSH (200 ng/mL final concentration). After washing to remove unbound ¹²⁵I-hFSH, cells were incubated for the indicated times at RT with buffer only (open squares, dashed lines) or with hCG (500 ng/mL final concentration) (filled triangles, solid lines). At the end of the incubation period, the amount of acid-precipitable ¹²⁵I-hFSH released into the medium was determined. Data shown are the mean ± SEM of triplicate determinations from one experiment representative of 4 independent experiments.